Page 41 - 2013 ISPAM Mid-Year Mtg Book

DRAFT – PREDECISIONAL Version 12.3
January 2013
Guidelines for Validation of Binary Qualitative Chemistry Methods Page 3
1.0 Scope
The purpose of this document is to provide a guideline for the validation of
binary1 qualitative methods intended to detect biological and chemical
compounds. Qualitative methods that are used to make a detection decision by
comparing the value of a response to a cut-off value should be validated by using
quantitative statistics, where possible, on the responses 2.
2.0 Terms and Definitions
Where appropriate, definitions have been taken from international standards and
the source is noted. Sources of definitions include the following:
ISO/IEC Guide 99:2007, International vocabulary of metrology – Basic and
general concepts and associated terms (VIM)
ISO 3534-2:2006, Statistics – Vocabulary and symbols – Part 2: Applied statistics
ISO 14971:2007, Medical devices – Application of risk management to medical
devices
ISO 17511:2003, In vitro diagnostic medical devices – Measurement of quantities
in biological samples – Metrological traceability of values assigned to calibrators
and control materials
ISO 5725-1: 1994, Accuracy (trueness and precision) of measurement methods
and results – Part 1: General principles and definitions
USP 31:2008, US Pharmacopeia General Information/<1223> Validation of
Alternative Microbiological Methods
Candidate Method
The method submitted for validation.
Matrix
Totality of components of a material system except the analyte (ISO 17511).
Method
A procedure that includes sample processing, assay, and data interpretation.
Probability of Detection (POD)
The proportion of positive analytical outcomes for a qualitative method for a given
matrix at a given analyte level or concentration. POD is concentration dependent.
1 A binary qualitative method is one that produces one out of two possible responses when it is used
(e.g., end time PCR, visual inspection of a dip stick).
2 The use of quantitative statistics usually gives better estimates of method performance for fewer
replicate analyses in each laboratory.